From inside the book

This book is very confusing and not clear about anything, which is the worst point.It lacks depth. Described a lot, but not in a effective manner.It seems like just a manual as It hardly talks about the mathematical formulation.Also, it is exhausting and very time consuming to read and after finishing I get confused.Right now, I usually roam internet to understand a topic rather than reading it.However I am just a PhD student, its all from my perspective.